Air in a 0.3-m3 cylinder is initially at a pressure of 10 bar and a temperature of 330 K. The cylinder is to 3 be emptied by opening a valve and letting the pres- sure drop to that of the atmosphere. What will be the temperature and mass of gas in the cylinder if this is accomplished? a. In a manner that maintains the temperature of the gas at 330 K? b. In a well-insulated cylinder? For simplicity assume, in part (b), that the process oc- curs suficiently rapidly that there is no heat transfer between the cylinder walls and the gas. The gas is ideal, and Cp 29 (J/mol K)

Explanation:

Since temperature is to be maintained ; constant temperature and a such, the process is ISOTHERMAL

b) Considering a well-insulated cylinder ;

Cp = 29J/molK

Temperature T2 = T1 [ P1/P2]^(1-γ)/γ

where γ = 1.4

plugging the values into the equation ; T2 = 171k

hence mass of the gas m1 = P1V/RT1

= 10 x 10^5 x 0.3/287 x 171

= 6.11kg

mass of m2 = P2V/RT2

= 10^5 x 0.3/287 x 171

= 0.611kg

hence required mass = m1 - m2

= 5.50kg

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.